Anthropogenic CO2, Will it destroy us?

I think everyone has done a great job of summarizing our trip to Cattle Point. From whizzing by the McCatchins in the van, to stumbling down the beach, and surviving to see the sunrise over Washington. I restrained and did not bring my camera in the interest of learning instead of photographing. However, we did get some good ones of the rockweed, Fucus gardneri, and its reproductive structures called conceptacles. See Jessica’s post below for a picture of me holding the thallus. For now, here is an H&E stain of the white reproductive conceptacle openings we all saw. How cool!

However, Fucus is not what I want to talk about. What interested me most was the red coralline algae, Corallina vancouverensis.

I had never seen any algae like this before. Corralina is a red algae from the order Corallinales which, as Hannah said, has calcium carbonate CaCO3 in its cell wall. When we discovered it, it was growing in the high intertidal tide pools, providing shelter and a home to numerous developing sea organisms. This role demonstrates the biological importance of such a unique species. This got me thinking about the effects of ocean acidification on such an important species that could potentially be degraded by the high acidities predicted to come.

So after a little research online, I came across one particular study that interested me, Effect of Carbon Dioxide Concentration on Calcification in the Red Coralline Alga Bossiella orbigniana . It was a study that grew a corraline algae in various concentrations of CO2. It showed increased calcification at increased dissolved CO2 levels (pCO2). Atmospheric CO2 is at about .04 % and is the rightmost point on the graph. As more CO2 is added, more calcification occurs (the graph increases as CO2 increases [moving left]). This shows an “acclimation” of this species to these higher levels. Hopefully, most species have an acclimation range; (I will tell you about the blue mussel’s acclimation or lack thereof at the end of the quarter). In my mind, this is nature’s way of buffering the amount of CO2 in the atmosphere. The study also describes increased growth in higher temperatures.

Acclimation is nature saying, “I understand you wanted to develop from my fossil fuels, but the moment you can get off of them, you must.”

Now, if you look, you’ll see that the rate of calcification decreases exponentially as CO2 concentrations reach .26% (over 6 times the present levels). A level that could possibly be attained if the world grows to 10 billion people and uses fossil fuels for energy. So it looks like Corallina will grow more quickly and uptake more CO2 for a while. This undermines conventional thinking that “more acidic waters will degrade the CaCO3 and cause species loss.” Furthermore, if this species is such and important home for developing organisms, maybe we will see an increase in other marine species. Maybe.

However, my short points are that: 1) the biological feedback loops on this planet are so complex that predictions are very limited and flawed; 2) we may see less species loss than predicted while we create a carbon neutral economy; and 3) if we don’t cut CO2 levels, we will definitely see detrimental effects.

I know the limitations of using only one study for making an argument, but think about what I’ve said and give yourself a pat on the back for being part of the solution. I’m optimistic there will be students studying Marine Biology in the generations to come, with the same amount of species diversity (maybe just a bit less).